Rockwell Automation Energy Management Accelerator Toolkit Quick Start - Manual (Page 439)

Rockwell Automation Publication IASIMP-QS016C-EN-P - October 2014 439
Appendix
D
Digital and Analog Energy Add-On Instructions
This appendix describes the behavior of all Digital and Analog Energy Add-On Instructions with the exception of the
Energy_Electric_Analog or Energy_Electric Digital Add-On Instructions, described in Appendix C.
The Digital and Analog Energy Add-On Instructions perform four functions.
• A total consumption calculation for the metered input. This value is stored in the output, Val_Total_xxx.
• A consumption rate calculation for the metered input over a predefined interval set by the user. This value, also
known as Average Flow rate, is stored in the output, Val_ xxx_Per_Calc_Interval.
• Equipment Status Faceplate update of the energy total Val_Total_xxx, the flow rate (Val_xxx_Per_Min or
Val_ xxx_Per_Hr), and energy device status information.
• Alarm History Faceplate update of information needed to display predefined alarm messages based on the energy
device status.
CompactLogix Digital Input Logic
Logic is provided in all Energy_ xxx_Digital Add-On Instructions to calculate energy consumption from CompactLogix
digital inputs. The Inp_Pulse tag initiates an energy computation, where 1 pulse = 1 (unit).
Every time a pulse is triggered, the logic adds the value of the Set_Meter_Pulse_Factor tag to the Val_Total_ xxx (total
consumption) tag. The Set_Meter_Pulse_Factor, is set by default to 1, but can be user-defined for scaling purposes.
Energy Add-On Instruction Unit
Air_Flow cf
Fuel_Oil gallons
Propane gallons
Steam_Flow lbs
Water_Flow gallons